The United Church of Canada was created in 1925, from the union of Presbyterian, Methodist, Congregationalist and Local Union churches. The women’s organizations from the uniting denominations at the time included: the Canada Congregational Woman's Board of Missions (mostly in eastern Canada, since 1886); the Women’s Missionary Society of the Methodist Church (founded 1876); the Woman's Missionary Society of the Presbyterian Church in Canada, Eastern Division (founded 1825) and Western Division (founded 1876); along with their various corresponding regional and local units. Soon after union, these became national, regional and local units of the United Church of Canada Woman’s Missionary Society (W.M.S.).

The new Society had its first annual meeting in 1926. Like the earlier societies, it brought the message of missions before the entire community of the Church, while offering financial support and personnel to its own wide mission programme.

In 1962, United Church W.M.S. and W.A. organizations across the country amalgamated to form the United Church Women (U.C.W.). Presbyterial and local groups developed along similar lines to national bodies, becoming local and presbyterial U.C.W. units in January 1962.